The present invention relates to an integrated optical and electric circuit device in which optical devices and electric devices are integrated on a semiconductor substrate.
The degree of integration of a semiconductor integrated circuit is increasing year after year and memories having a few megabits on a chip of a few square millimeters have been developed recently. At present, integrated circuits have problems such as signal delay due to an increase in the length of electrical interconnections and in load in a high-density packing state, and an increase in designing and manufacturing costs due to interconnection complications.
In integrated digital circuits, a clock signal is a most fundamental signal in operation. Although it is necessary in a chip to simultaneously distribute the clock signal (common signal of a system) to logic circuit units, it is difficult to attain such a simultaneous distribution of the clock signal under the high-density packing state due to the foregoing signal delay. Since the clock signal is supplied to each logic circuit unit, the ratio of an area required for the interconnection of the clock signal in the chip to an area of another circuit interconnection becomes large, causing an obstacle to realize a very high density integration.